{
  "id": "shielding:shielding-foil",
  "collection": "shielding",
  "slug": "foil",
  "name": "Aluminium foil and foil-faced board",
  "summary": "A continuous metal layer is a near-perfect RF barrier in principle — 40 dB and better — but seams, staples and penetrations mean installed performance is governed entirely by workmanship.",
  "status": "verified",
  "lastVerified": "2026-08-12",
  "data": {
    "aliases": [
      "aluminium foil shielding",
      "foil insulation board"
    ],
    "form": "foil",
    "attenuation": {
      "value": 30,
      "max": 60,
      "band": "broadband, workmanship dominated",
      "sourceIds": [
        "sbm-2024"
      ]
    },
    "targets": [
      "radiofrequency"
    ],
    "requiresGrounding": true,
    "failureModes": [
      "Unbonded seams behave as slot apertures and can leak more than the surrounding material blocks",
      "Creates a vapour barrier where none was designed, risking condensation inside the build-up",
      "Ungrounded foil can increase AC electric field readings in the room"
    ],
    "related": [
      "shielding:paint"
    ]
  },
  "sources": [
    {
      "id": "sbm-2024",
      "title": "Building Biology Evaluation Guidelines for Sleeping Areas (SBM-2024)",
      "publisher": "Institut für Baubiologie + Nachhaltigkeit (IBN)",
      "url": "https://buildingbiology.com/site/downloads/SBM-2024_EVALUATION_GUIDELINES_EN.pdf",
      "year": 2024,
      "kind": "ngo",
      "retrieved": "2026-08-12"
    }
  ],
  "links": {
    "self": "https://emfbase.com/api/shielding/foil",
    "html": "https://emfbase.com/shielding/foil",
    "markdown": "https://emfbase.com/shielding/foil.md",
    "collection": "https://emfbase.com/api/shielding"
  }
}